Apparatus for determining the resistance of the ground



Sept. 20, 1938..

C. P. J. M. VAN DER MEER APPARATUS FOR DETERMINING THE RESISTANCE OF THE GROUND Filed March 3, 1936 INVENTOR (anslmz Z J? J M Vanda/Myer BY V ATTORNEYS Patented Sept. 20, 1938 PATENT OFFICE APPARATUS FOR DETERIVIINING THE RE- SISTANCE OF THE GROUND Constant Pierrejean Marie Van der Meer, Brussels, Belgium Application March 3, In Belgium 2 Claims.

My present invention relates to apparatus used in order to determine the resistance of the ground to the static pressure of structures or works of any kind which it is called upon to support.

The apparatus employed up to the present for V determining data of this kind are based on the very approximate observation of the penetration of a table loaded generally by hand or of the penetration of a 10 tain height.

In the apparatus of the first type a table of known section is used supporting a load of several tons composed cement, or of pig iron. guided in a rigid manner, is

body falling freely from a cer-' either of sacks of sand or The table not being liable to tilt and thus make incorrect the vague indications which it gives.

n the other hand the apparatus based on the free fall of a body give indications which can be disputed seeing that nothing proves that any ground reacts in the same manner under shock and under a static charge.

My present invention has for its object to overcome these inconveniences and to obtain an apparatus which is light and portable, allowing With this object in view,

tially consists in my invention essenthe special arrangements and combination of parts hereinafter fully described and pointed out in the appended claims.

0n the annexed drawing:

Fig. 1 is a vertical section through the apparatus at the moment when it is placed on the ground.

Fig. 2 shows in section this apparatus after the piston has penetrated a certain distance into the ground.

Fig. 3 is a view partly in section taken along the line 3-3 of Fig. 1. Fig. 4 illustrates the method of mounting a supplementary cylinder for measuring the speed of penetration.

As can be seen from these figures, the apparatus comprises a piston l of suitable cross sectional area projecting from a supporting plate 2 placed on the ground and loaded either by the operator himself make it rigid. The piston l extremity of a rod 3 sliding upper extremity other load so as to is mounted at the in a tube 4 and the 5 of which is acted upon by a or by some spring 6 compressed by a head 1 receiving the thrust of a screw 8 actuated by a hand wheel 9.

March 6, 1935 The extremity 5 of the rod 3 is rigidly connected with a carriage l0 carrying on the one hand two scales l2 and I3 and on the other hand a cylinder l4 capable of turning about its vertical axis l5, and the cylinder I4 is provided with a drum or pulley A over which is looped an endless cord l6 which passes upwardly over the pulleys ISA and thence downwardly over the upper pulleys I63 thence over the pulley 160 which is directly behind the pulley ISA and then around the drum A. The cord is attached to the index l9 and, as the carriage moves relatively thereto, the cord rotates the drum [4A. This cylinder l4, which can be removed in a minute, contains the spare bands of paper.

The scale l2 moves in front of a fixed index l8 whereas the index l9 rigid on the head I shifts in front oi the scale I3. A tracer or pencil holder 20, mounted on a fixed centre but adjustable in a vertical plane by means of a pressure screw cooperates with the recording cylinder H. The whole of the mobile pieces are balanced by a counterweight 2| so as to avoid errors due to the weight of these pieces.

It is easy to see under these conditions that by manipulating the hand wheel 9 the head I descends in the tube 4 and exerts, through the intermediary of the spring 6, a pressure on the piston l which tends to force its way into the ground. The reading of the force is made on the scale l3 whereas that of the penetration of the piston is taken on the scale l2.

The pressure and penetration are moreover inscribed on the recording cylinder H by the tracer 20; the pressures being indicated by abscissae and the penetrations by ordinates.

This apparatus may if desired be completed by a cylinder destined to measure the speed of penetration. In this case a second cylinder 22 is provided which is actuated by a clockwork movement of some kind. Aben't rod 23 connected to the extremity 5 of the piston and guided at its upper end, carries a tracer 24 which inscribes the penetrations of the piston at the moments they take place.

The apparatus also comprises a handle 25.

The diagrams obtained with the aid of the apparatus enable the limit of elasticity or fracture of the ground to be determined quickly and constitute permanent documents. The manipulation of the apparatus requires no scientific knowledge; its small size and light weight make it portable and enable it to be easily lowered to the bottom of a well for example, to the depth provided for the foundations.

It is advisable to mention that the essential advantage of the apparatus is that it is portable and or small size. Its height is generally '18 cm. and its total weight 11.7 kgs.

What I claim is:

1. In a portable apparatus capable of measuring the resistance of the ground, in combination, a piston, a pressure member whereby a pressure is exerted on the. said piston in order to produce its penetration into the ground, a spring interposed between the piston and the pressure member, means whereby the vertical movements oi the piston, 01' the pressure member and of the spring are guided, a carriage made rigid with the piston, a double scale carried by the said carriage, a fixed-index cooperating with one of the scales whereby the penetrations performed are indicated, a second index rigid with the pressure member and moving in front 01' the other scale, whereby the pressures exerted on the piston are indicated, a recording cylinder carried by the said carriage, means whereby the said cylinder is rotated by the movement of displacement of the pressure memberorelative to the piston, a tracer in front of which the recording cylinder moves vertically during the penetration of the piston. turning about its axis upon said displacement oi the pressure member.

2. Apparatus capable of measuring the resistance of ground comprising in combination, a

piston, means 'for exertingpressure on the piston recording instrument indicating both the pressure upon and penetration of the piston, and means attached to said carrier for counterbalancing the weight of said carriage.

CONSTANT PIERRE JEAN MARIE VAN nna MEER. 

